John Lam

Title: John Lam - Innovator in Electronic Ballast and LED Technology

Introduction

John Lam is a notable inventor based in Kingston, Canada. He has made significant contributions to the fields of electronic ballasts and LED technology. With a total of 5 patents to his name, Lam's work focuses on enhancing the efficiency and functionality of lighting systems.

Latest Patents

One of Lam's latest patents is a digital controller for an electronic ballast. This invention provides circuits and methods for controlling a fluorescent lamp's electronic ballast. It features a feed-forward loop that offers information about a voltage firing angle and a pulse width modulator that regulates the duty ratio of at least one power switch. The digital controller includes various functions such as dimming, maintaining a high power factor throughout the dimming range, low lamp power detection, lamp soft-start, and DC-link capacitor over-voltage detection for end-of-life protection or lamp failure protection. In one embodiment, the ballast is designed as a single-stage, single-switch ballast.

Another significant patent is a high power factor, electrolytic capacitor-less driver circuit for light-emitting diode lamps. This driver circuit employs a rectifier, a power factor correction subcircuit, a voltage conversion subcircuit, and a semiconductor switch. The power factor correction subcircuit utilizes a film capacitor instead of an electrolytic capacitor, and it shapes the incoming current to a substantially sinusoidal waveform that is in phase with the input AC current. The semiconductor switch generates a high-frequency pulsating triangular current at the output of the rectifier.

Career Highlights

Throughout his career, John Lam has worked with various organizations, including Queen's University at Kingston. His innovative work has significantly impacted the development of efficient lighting technologies.

Collaborations

Lam has collaborated with notable individuals in his field, including Praveen Jain, enhancing the scope and impact of his inventions.

Conclusion

John Lam's contributions to electronic ballast and LED technology demonstrate his commitment to innovation and efficiency in lighting systems. His patents reflect a deep understanding of electrical engineering and a dedication to improving energy use in modern lighting solutions.